motor neuron Nerve carrying messages to the muscles from the brain via the spinal cord. The cell bodies of some motor nerves form part of the spinal cord. Motor nerves are involved in both reflex action and voluntary muscular control. Motor neuron disease (MND) is a degeneration of nerve cells that causes muscle loss and eventual death.

motor neuron A neuron that transmits nerve impulses from the central nervous system to an effector organ (such as a muscle or gland) and thereby initiates a physiological response (e.g. muscle contraction).